Interconnected data centers, such as those implemented using Data Center Interconnect (DCI) from Cisco Systems, Inc., are typically configured with a distributed anycast gateway and an enhanced forwarding mode that can be enabled for any subnet. Such a configuration facilitates routing both intra and inter-subnet traffic in generally the same consistent manner to optimize forwarding within a network fabric. The configuration also provides localization of the broadcast domain and prevents flooding within the fabric.
Multi-Protocol Border Gateway Protocol (MP-BGP) is typically used as the control protocol of choice to distribute host addresses within a given data center fabric. Consequently, traffic can be optimally forwarded to the appropriate top of rack (ToR) switch below which the destination host resides. The host route distribution also restricts a ToR switch or “leaf” to proxying for only “known” remote destinations.